1. Field of the Invention
The present invention relates to an electrode for electrochemical uses and, more particularly, to an electrode made of metal mesh coated with diamond-like carbon or dirty diamond.
2. Description of the Related Art
In recent years, there has been an increasing interest in the electrochemical properties of diamond and boron-doped diamond coated substrates, primarily due to the excellent resistance of this material to chemical degradation and, as a result, its dimensional stability. The physical and electrochemical properties of boron-doped diamond have been described in the following patents and publications incorporated herein by reference: U.S. Pat. No. 5,399,247 to Carey; U.S. Pat. No. 5,900,127 to Iida et al; Swain, xe2x80x9cThe Electrochemical Activity of Boron-Doped Polycrystalline Diamond Thin Film Electrodesxe2x80x9d Anal. Chem 1993, 65 pp 345-351; DeClements and Swain, xe2x80x9cThe Formation and Electrochemical Activity of Microporous Diamond Thin Film Electrodes in Concentrated KOHxe2x80x9d, J. Electrochem. Soc., Vol 144, No. 3 Mar. 1997, pp 856-866; Swain xe2x80x9cThe Susceptibility to Surface Corrosion in Acidic Fluoride Media: A Comparison of Diamond, HOPG, and Glassy Carbon Electrodesxe2x80x9d, J. Electrochem. Soc., Vol 141, No. 12, December 1994, pp 3382-3393; Tenne et al, xe2x80x9cEfficient Electrochemical Reduction of Nitrate to Ammonia Using Conductive Diamond Film Electrodesxe2x80x9d J. Electroanal. Chem 347 (1993) pp 409-415; Awada, xe2x80x9cElectrodeposition of Metal Adlayers on Boron-Doped Diamond Thin-Film Electrodesxe2x80x9d J. Electrochem Soc., Vol. 142, No. 3 March 1995, pp L42-L45; Martin et al, xe2x80x9cHydrogen and Oxygen Evolution on Boron-Doped Diamond Electrodesxe2x80x9d J. Electrochem. Soc., Vol 143, No. 6, June 1996, pp L133-L136, and Glesener et al xe2x80x9cFabrication of High Surface Area Boron-Doped Diamond Coated Tungsten Mesh for Electrochemical Applicationsxe2x80x9d Material Letters 37 (1998), pp 138-142.
It has now been discovered that diamond-like carbon or diamond with non-diamond carbon inclusions, which is also known as dirty diamond, can be used in the fabrication of a high surface area electrode. This is done by forming a coating of diamond-like carbon or dirty diamond on a conductive metal mesh substrate. The mesh structure allows for enhanced mass transport of reactants when used as an electrode in an electrochemical cell. The use of conducting metal as the material that makes up the mesh substrate improves the conductivity and energy efficiency of the electrode. The diamond-like carbon or dirty diamond coating provides for enhanced dimensional stability and corrosion resistance for the mesh structure.
A further aspect of the current invention is a method of electrochemically reducing an organic of non-organic solute in a liquid solution, by providing an electrochemical cell, which includes a liquid solution containing an organic or non-organic solute and an electrode comprising a conductive metal mesh substrate coated with diamond-like carbon or dirty diamond, then charging the electrode as a cathode, and exposing the liquid solution to the electrode.
A further aspect of the current invention is a method of electrochemically decomposing an organic of non-organic solute in a liquid solution, by providing an electrochemical cell having an electrode comprising a conductive metal mesh substrate coated with diamond-like carbon or dirty diamond, applying an alternating current to said electrode and exposing the solute to the electrode.
A further aspect of the present invention is a method of electrochemically decomposing an organic or non-organic solute in a liquid solution by providing an electrochemical cell including a liquid solution containing an organic or non-organic solute and having an electrode comprising an conductive metal mesh substrate coated with diamond-like carbon of dirty diamond and having means to expose the electrode to the liquid solution and charging the electrode as an anode.